Mandible & maxilla
Odontogenic cysts
Radicular (periapical) cyst
Last author update: 1 March 2014
Last staff update: 29 September 2022
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PubMed Search: Periapical (radicular) cyst [title]
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Pathophysiology | Clinical features | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosis | Additional referencesCite this page: Morrison A. Radicular (periapical) cyst. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/mandiblemaxillaperiapicalcyst.html. Accessed March 22nd, 2023.
Definition / general
- Inflammatory odontogenic cyst
- Lined by epithelial cells derived from rests of Malassez
- Also called radicular cyst, apical periodontal cyst, root end cyst, or dental cyst
Terminology
- Epithelial rest of Malassez:
- Derived from Hertwig epithelial root sheath
- Small spherules of 6 - 8 epithelial cells with high nuclear to cytoplasmic ratio
- Little or no reverse polarity of cells
- Periapical cyst: present at root apex
- Lateral radicular cyst: present at the opening of lateral accessory root canals
- Residual cyst: remains even after extraction of offending tooth
- Periapical granuloma: chronic granulomatous inflammation of periapical tissues
Epidemiology
- Most common odontogenic cyst (52% of jaw cystic lesions)
- Most common in 4th & 5th decades, but occurs over wide age range
Sites
- 60% in maxilla (vs. mandible)
- Most commonly in apex of lateral incisors, but also along lateral accessory root canals
Pathophysiology
- Dental caries or trauma cause chronic inflammation which eventually forms a periapical inflammation; continued inflammation stimulates cells of the rests of Malassez, the epithelial cells undergo necrosis to form the cyst which may be sterile or become secondarily infected
- While most are lined by epithelium derived from rests of Malassez, epithelial lining may be respiratory type derived from the maxillary sinus, in the setting of a periapical lesion communicating with the sinus wall
- May be oral epithelium from a fistula or oral epithelium proliferating down a periodontal pocket
Clinical features
- May be asymptomatic and incidentally found with radiographs
- Possible swelling (occurs slowly)
- May be painful if infected
Radiology description
- Round to oval radiolucency, often with well defined cortical border (this border can be lost when infected)
- Can displace or reabsorb roots of adjacent teeth if large
Radiology images
Images hosted on other servers:
Radicular cyst
Radicular cyst, root partially reabsorbed
Upper maxilla
Periapical cyst involving maxillary anteriors
Progressive involution of periapical lesion
Prognostic factors
- Dependent on tooth affected, size of cyst / extent of bone destruction and accessibility for treatment
- Rare complications:
- Squamous cell carcinoma and epidermoid carcinoma may arise from the epithelial lining of periapical cysts
- Pathologic bone fracture (occurs with large cysts that erode nearly completely through the jaw)
Case reports
- 8 year old boy with radicular cyst followed by incomplete pulp therapy in primary molar (J Indian Soc Pedod Prev Dent 2013;31:191)
- 8 year old boy with radicular cyst (Case Rep Dent 2013;2013:123148)
- 10 year old girl with nonsurgical management of a periapical cyst (J Int Oral Health 2013;5:79)
- 18 year old woman with radicular cyst with severe destruction of the buccal cortical plate secondary to endodontic failure (J Clin Diagn Res 2013;7:1816)
- 39 year old man with eosinophilic granuloma in the anterior mandible mimicking radicular cyst (Imaging Sci Dent 2013;43:117)
- 55 year old woman with squamous odontogenic tumor-like proliferation in a radicular cyst (J Clin Exp Dent 2013;5:e298)
Treatment
- In adult teeth, can treat necrotic pulp (infection source) via pulpectomy ("root canal") with sparing of the tooth; this induces involution of the cyst; can also extract tooth
- In some very large cysts, after above treatment, additional surgical management (enucleation or marsupialization) is required for the osseous cyst
Clinical images
Images hosted on other servers:
Palatal swelling
Lateral mandibular lesion
Gross description
- Usually attached to tooth root, may be firm or have deflated capsule, lumen can contain thin serous or straw colored fluid, opaque yellow-white debris, muddy brown fluid from old hemorrhage or frank purulent debris
Microscopic (histologic) description
- Lined by stratified squamous epithelium of variable thickness, often with scattered ciliated cells
- Exception is when epithelium is derived from maxillary sinus and thus lined with respiratory epithelium (pseudostratified ciliated columnar epithelium), may have acute inflammatory cell infiltrate
- Rushton hyaline bodies: amorphic, eosinophilic, linear to crescent shaped bodies, found in epithelium of 10% of periapical cysts
- Fibrous capsule: varying thickness with chronic inflammatory cells, plasma cells may be particularly prominent
- Cholesterol clefts are common within cyst lining
Microscopic (histologic) images
Contributed by Kelly Magliocca, D.D.S., M.P.H.
Radicular cyst
Images hosted on other servers:
H&E
Cyst
H&E
Differential diagnosis
- Influenced by degree of inflammation, anatomic location of cyst, amount of cystic epithelium present (incisional biopsy vs complete enucleation)
- Inflamed developmental odontogenic cyst
- Periapical granuloma
- Surgical ciliated cyst
- Traumatic bone cyst
Additional references
